mlxsw: switchib: Introduce SwitchIB and SwitchIB silicon driver

SwitchIB and SwitchIB-2 are Infiniband switches with up to 36 ports. This
driver initialize the hardware and Firmware which implements the IB
management and connection with the SM.

Signed-off-by: Elad Raz <eladr@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>